Add a inner text parameter to ContextMenuParams

This CL adds a parameter to ContextMenuParams, the inner text of a link on
which a context menu is opened.

BUG=591365

Review-Url: https://codereview.chromium.org/2379653002
Cr-Commit-Position: refs/heads/master@{#423814}

ios/web/public/web_state/context_menu_params.h

@@ -38,6 +38,10 @@ struct ContextMenuParams {
 
   // The location in |view| to present the menu.
   CGPoint location;
+
+  // The text associated with the link. It is either nil or nonempty (it can not
+  // be empty).
+  base::scoped_nsobject<NSString> link_text;
 };
 
 }  // namespace web

ios/web/web_state/js/resources/core.js

@@ -188,7 +188,8 @@ goog.require('__crWeb.message');
           // Found a link.
           return {
             href: element.href,
-            referrerPolicy: getReferrerPolicy_(element)
+            referrerPolicy: getReferrerPolicy_(element),
+            innerText: element.innerText
           };
         }
 

ios/web/web_state/ui/crw_web_controller.mm

@@ -4290,6 +4290,10 @@ const NSTimeInterval kSnapshotOverlayTransition = 0.5;
     params.referrer_policy =
         web::ReferrerPolicyFromString(base::SysNSStringToUTF8(referrerPolicy));
   }
+  NSString* innerText = element[@"innerText"];
+  if ([innerText length] > 0) {
+    params.link_text.reset([innerText copy]);
+  }
   return params;
 }